Some may say Mr Mousavi's case is unique because he is a politician, but he believes ordinary Iranians are just as easily pursued by authorities.

Australian government figures support that. So far this year, 5,541 people have arrived in Australia, up from 2,749 in 2012.

"Lots of people [fled] since 2009, especially after the presidential election and crackdown of the government increased," he said.

"The freedom of expression is very bad in the country and since 2004 especially until now. Actually most of the people who left the country, they left because of that limitation."

Amnesty International's refugee spokesperson Graham McGregor says political persecution is just one reason authorities pursue people in Iran, but there are many others.

"Human rights abuses are still very widespread and are still carried out against both individuals and social groups," he said.

"The authorities still in Iran still can seem to discriminate really pretty harshly against non-Shia minorities, including other Muslim communities.

"The Kurds and a number of other ethnic minorities are all discriminated again in a similar way to women - both in law, so they don't have the same legal rights as the rest of the population, but they're also discriminated against on a day-to-day basis in terms of access to employment or education."

The Immigration Department says asylum seekers from Iran claim persecution on the grounds of their political opinion, race or religion.

However, Senator Carr took a different line when he said most arrivals were economic migrants.

Worsening Iranian economy a factor in refugee arrivals

The economic situation in Iran is a factor for many with inflation more than 30 per cent and the unemployment rate sitting above 10 per cent since 1997.

Mr Mousavi says these issues are also a reason why people leave.

"After eight years of governing the country by Ahmadinejad, the economy is very bad and inflation and unemployment it increased," he said.

But if political persecution and the economy aren't enough, some say international sanctions in response to the country's nuclear program are also playing a role.

Western countries, including Australia, have been slapping Iran with new sanctions every year since 2006.

Reza Marashi from the National Iranian American Council says the affect of these sanctions cannot be underestimated.

"You're hearing an increasing number of stories of medical supply shortages inside of Iran," he said.

"You see the prices of food increasing, you see the prices of automobiles, you name it; typical day-to-day items that many of us in the West take for granted all becoming far more difficult for Iranians to afford and access.

"The sanctions that have been put in place by the United States and other Western countries, Australia included, increasingly are the primary reason why life has become so much more difficult than it used to be even one or two years ago inside of Iran."